Survey on the current status of sand lobster (Thenus orientalis) exploitation and consumption in Nam Du Island and around the Ha Tien Sea area was conducted from January 2020 to May 2020. Through interviews with 40 households who are engaged in fishery exploitation. The results show that sand lobster is not the main target of fishing vessels, as the production of shrimps in the Nam Du archipelago and around Ha Tien waters tends to decrease sharply-in terms of composition, size as well as production. The majority of sand lobster (Thenus orientalis) production concentrated in May and June. Average production of shrimp caught in one trip was 13.30 ± 24.24 kg, the highest was 90 kg/trip and the lowest was 1 kg/trip depending on the time of a sea trip. The main difficulty of the job is that bad weather affects the exploitation and natural shrimp resources have significantly decreased. For the consumption of sand lobster, the highest yield is 7.5 tons/year and the lowest is 0.4 tons/ year. The average total cost of purchasing sand lobster (Thenus orientalis) is 823.48 ± 530.28 VND/year and the total income is 724.65 ± 450.33 VND/year with a cost-benefit ratio of 0.88 ± 0.85.

Investigating the species composition and proximate compositions of sea cucumber Stichopus Brandt, 1835 (Stichopodidae) in Nam Du island, Kien Hai district of Kien Giang province was conducted from March to December 2018. During six sampling times, 6 sea cucumber species were found namely S. variegatus, S. hermanni, S. chloronotus, S. horren, S. naso, and S. monotuberculatus, of which S. variegatus was most dominant followed by S. hermanni; these two species were recorded in all sampling times. S. naso and S. chloronotus were only observed once with the lowest proportion (0.38%) compared to all specimens. The proximate composition of four common Stichopus species (S. variegatus, S. hermanni, S. horren and S. monotuberculatus) varied greatly, with average moisture contents ranging from 87.61 to 89.35%, crude protein: 41.28-53.27%, crude lipid: 0.93-2.57%, ash: 18.95-31.75%, fiber: 0.64-0.83%, carbohydrates: 12.93-30.19%, calcium: 0.92-1.69% and phosphorus 0.35-0.67% of dry weight. Notably, S. variegatus and S. hermanni had significantly higher protein contents than other species, and S. hermanni has the highest lipid content.

Acute hepatopancreatic necrosis disease (AHPND) is one of leading cause of mass mortality in cultured shrimp yearly, caused significant increases in antibiotic application in shrimp farming. To reduce the use of antibiotic in shrimp farming, the study was conducted to evaluate the effect of dietary supplementation of the extract from pomegranate (Punica granatum) leaves on growth performance, immunity index and resistance of AHPND in whiteleg shrimp (Litopenaeus vannamei). The research was carried out in 4 weeks with different supplementations, including control treatment, 1% P. granatum and 2% P. granatum. Results showed that (i) dietary supplementation of pomegranate extract could increase the growth rate and innate immunity of whiteleg shrimp; (ii) dietary supplementation of 2% pomegranate extract could significantly increase survival rate of whiteleg shrimp after being challenged to Vibrio parahaemolyticus. The obtained results suggested potential applications of the pomegranate extract in commercial shrimp farming.

The study was conducted to determine the diversity of macroinvertebrates and apply the BMWPVIET-HR score system to assess water quality in the aquaculture area on the Hau River of Can Tho city and An Giang province. The study consisted of two sampling times (March and June, 2019).  Macroinvertebrates were sampled at 19 sampling locations including 9 locations in Can Tho City and 10 locations in An Giang province. The results showed that a total of 62 species belonging to 33 families of macroinvertebrates on the Hau River were found. In which, Gastropoda was the most diverse (11 families, 33%), followed by Insects (10 families, 30%), others varied from 1-5 families (3-15%). Species composition at the sampling locations ranged from 7-20 species and 6-18 species for March and June periods, respectively. The biological indices fluctuated from 18-51 scores for BMWPVIET-HR   and 2.6-4.9 scores for ASPT indicated that water quality in most sampling locations had moderate pollution. Some sampling sites on June, 2019 like Thanh My, Cai San, Ben pha Bo Ot (Can Tho city), Con Khanh Hoa and Ben pha Rach Goc (An Giang province) were heavily polluted.

A study on the nutritional characteristics of Redspine threadfin bream Nemipterus nemurus (Bleeker, 1857) was conducted from June to December 2019 in coastal areas from Soc Trang to Bac Lieu provinces. Fish samples were collected monthly by a bottom trawler with 2 size groups including big fish group (215 spawning individuals – Total body length from 170.8 to 340.0 mm) and small fish group (55 adults-Total body length from 121.5 to 169.4 mm). The fish's stomach was collected and fixed in formaline 10% immediately after catch. Total body length of fish and the intestine length of fish were measured by method of Nikolsky (1963) and maxillary length of fish was measured according to Shirota (1970). The results showed that the fish have wide mouth, long mouth and slanting; the jaw is very developed; gill rakers were sparse, short and hard to hold feed; esophagus was short, thick wall, with many folds; stomach was greatly expanded with the posterior portion, forming as a long sac, thick wall and many folds inside; caeca has 8-10 tubes with a sealed end attached to between the stomach and intestines; intestine was short, thick wall and folded. Relative length of the gut (RLG)

This experiment on nursing of pompano (Trachinotus blochii) fish fingerlings at different stocking densities in recirculating water system was conducted at the College of Aquaculture and Fisheries, Can Tho University from December 2018 to January 2019. The experiment had four treatments with different densities of 60; 90; 120 and 150 individuals/m3 and was designed with 3 replications. Pompano fingerlings with initial body weight of 2 g were reared in 500-L plastic tanks at water salimity of 20‰ and were continuously aerated. Fish were daily fed with pelleted feed (44% protein) at rate of 15% total body weight. After 30 days of rearing, treatment with 150 individuals/m3 showed the best results in growth rate (0,26 g/day and 5,30 %/day) and was significantly higher than those of the other treatments (p

Aquaculture is the strength of Mekong Delta. How to determine the origin and quality of aquaculture product in the market is of great interest to consumers and authorities. This article proposes to build an information system that supports traceability of seafood by QR code (Quick Response code). To implement the process in the system, a farmer firstly registers a corresponding QR code for his/her product, then updates the changes during the farming process (for example, following the Vietnamese GAP model). When harvested, the product (raw or processed) will be pasted with a QR code before being distributed to the market. Consumers who buy the product can easily retrieve farming information through scanning the QR code by a smartphone. In addition, the system also manages and introduces seafood in the Mekong Delta to help users search and find information. After analyzing, designing, constructing and testing the system on some sample data, the results showed that the completion and applying are very promising.

With a view to becoming the national shrimp capital, authorities in Bac Lieu has oriented the development and applications of science and technology in shrimp industry. Bac Lieu province is known as a one of the most developed aquaculture areas in the Mekong Delta region with various systems such as semi-intensive, intensive, and super-intensive shrimp farming. Therefore, the aim of this study was to assess the quality of water supply resources surrounding shrimp culture ponds to provide fundamental understanding about the spatial and seasonal variations of water quality in Bac Lieu where the shrimp culture has been intensified. Water samples were monthly collected at 5 sites in key features of estuaries in the shrimp culture area of the province over a year. Results showed that the water quality in the shrimp farming area is fewer fluctuations, still qualified the requirements of the national standards, and suitable as water supply for shrimp culture in the research area. However, it could be noted that concentrations of TSS, H2S, and PO43- were relatively high compared to the standards for marine shrimp. Considering the BL1 (Nha Mat estuary - Bac Lieu city) and BL5 (Ganh Hao estuary - Dong Hai) sites, most water quality parameters were highly fluctuated among the seasons. Additionally, poor water quality occurred in the dry and dry-rainy seasons at the Ganh Hao estuary (site BL5). 

The study was conducted to evaluate the use of Phyllanthus amarus Schum. and Thonn extract in the quality of the black tiger shrimps under ice storage. The experiment consisted of three treatments. Shrimp (25-30 g) were soaked in P. amarus extract solution with concentrations of 7.71 mg/mL and 156 mg/mL or in iced water (control treatment) at 0-4°C for 30 minutes. Shrimps after soaking were stored in ice and samples were collected on days 1, 4, 8, and 12. Changes in shrimp quality were evaluated through total aerobic bacteria count, sensory analysis, elasticity, water holding capacity, total volatile base nitrogen, peroxyde value, thiobarbituric acid reactive substances, moisture and pH. The results showed that black tiger shrimp treated with P. amarus at concentration of 7,71 mg/mL and 156 mg/mL showed significantly higher sensory properties, and slighly lower primary and secondary oxidation products and total aerobic bacterial counts compared to the control samples during ice storage. Based on the sensory properties and total aerobic bacteria count, black tiger shrimps can be used up to 8 days.

This study is aimed to observe the reproductive biology of Coilia rebentischii distributed from downstream of the Hau river (one of the branches of the Mekong River) to the estuary of Dinh An and Tran De, in order to supplement the existing scientific data and to serve as a basis for research on artificial reproduction. The study was conducted from July 2019 to June 2020 by collecting fish samples in three sites from downstream of the Hau River and the estuary of Dinh An and Tran De; the sampling cycle time was once a month by trawl net, bag net and landing net, a number of fish about 40 individuals per month. The results showed that gonadosomatic index (GSI) of Coilia rebentischii ranged from 1.10 to 6.92% and was more fluctuated than hepatosomatic index (HSI) (from 0.21 to 1.20%); conditional factor (CF) of fish was also less fluctuating, in which CF reached the highest value in November. Fecundity of Coilia rebentischii ranged from 218-943 eggs/g of female (mean=495±197 eggs/g) with total length was 10.4±1.8 cm and total weight was 16.01±8.05 g. First length mature of female was 11.05 cm and male was 13.69 cm. The results also show that the breeding season of Coilia rebentischii begin from June to November and is most concentrated from June to July of the year. This shows that healthy fish is a species that has the potential to develop as a target for breeding because their breeding season is quite...

The study is aimed to identify macrophyte with capability of wastewater treatment in a recirculating aquaculture system. There were 4 treatments including Pistia stratiotes, Lemna minor, Limnobium laevigatum, and the control treatment (no plants). Broadhead catfish, Clarias macrocephalus (weight of 60 g each) were stocked at a density of 70 fish/100L and fed to ad libitum with floating pellets (41% crude protein). The results revealed that Pistia stratiotes was the best macrophyte in treating wastewater discharged from the broadhead catfish culture system in the first 10 days of the experiment. The concentration of CO2, COD, TAN, N-NO3-, P-PO43-, and TP in wastewater reduced   65.83%, 34.28%, 40.70%, 46.70%,  24.56%, and 9.16%, respectively while dissolved oxygen increased 37.68% compared to the initial concentration after treatment by Pistia stratiotes.

Using solar energy in aquaculture is one of the encouraged solutions in sustainable development. This paper aims to introduce and provide a method of implementing the algorithm to detect and track the maximum power point of photovoltaic panels (solar panels) based on the conductivity of the panel (Incremental Conductance Maximum Power Point Tracking - Ind. Cond. MPPT). This is an important part of creating a basis for deploying solar energy in aquaculture ponds, especially addressing the energy needs of the paddle wheel aerator for shrimp ponds (for oxygen supply and water stirring), because it helps maximize the extracted energy from solar panels. Based on the theory of the electrical model of the photovoltaic panel, the Incremental Conductance algorithm is implemented in the interleaved boost DC-DC converter topology controlled by a programmable digital controller (STM32F1 microcontroller unit). The results of the implementation show that the voltage at the maximum power point of the panel array is always stably maintained, the extracted power is controlled to track the maximum available power of the panel array, the system with the Ind. Cond. The MPPT algorithm is stable and does not get stuck into the transfer characteristic transient region of the DC-DC converter.

This study was carried out to determine the effects of essential oils Citrus as anti-fungal agents on Achlya sp. Essential oils were extracted from peels of Citrus aurantifolia, Citrus limon (L.) Burn.f.1768, Citrus grandis var. Da xanh, Citrus grandis var. Nam roi, Citrus nonbillis and Citrus sinensis by hydrodistillation method. The antifungal activity, minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of essential oils were examined against snakehead pathogenic fungi Achlya sp. A.1910 and Achlya sp. A.1924 isolated from snakehead fish. The essential oils of C. aurantifolia and C. sinensis that was found to be the most active against Achlya sp. were 0.78 mg/mL after 24 h exposure. The MIC of essential oils of C. grandis var. Nam roi and C. limon was from 1.56 – 6.3 mg/mL. Antifungal activity of essential oils was C. aurantifolia, C. sinensis, C. grandis var. Nam roi, and C. Limon respectively. The hyphae of Achlya sp. was completely inhibited when they were exposed to 100, 50, 25 and 12.5 mg/mL of essential oils Citrus.

The The study is aimed to isolate and screen potential actinomycetes from shrimp pond sediments that being capable of biodegradation and antimicrobial activity against Vibrio parahaemolyticus in vitro. Total of 40 sediment samples were collected in extensive shrimp ponds located in Tra Vinh, Bac Lieu and Ca Mau province. Results showed that 161 strains were able to grow on Starch Casein Agar (SCA) medium, in which 54 strains were identified as Streptomyces genus with the characteristics of gram-positive cell, catalase positive, oxidase negative and spore formation. Out of the 54 Streptomyces isolates, 12 strains performed the antimicrobial activity against Vibrio parahaemolyticus with a mean inhibition zone ranged from 2.3 to 32.8 mm, especially 04 strains, CM1.1, CM2.4, DH3.4 and TV1.4 possessed the largest zone. In addition, DH3.4 strain was greatly potential for the relatively high enzyme activities such as α-amylase, protease and cellulase. Therefore, these strains could be used for in vitro and in vivo further experiments in aquaculture.

Panna microdon, one of the economic species in the Mekong Delta, has high meat quality and is usually consumed as fresh or dried products. Study on the feeding biology of P. microdon was carried out from June 2019 to April 2020 in the coastal areas of Soc Trang and Ca Mau provinces. Samples in various sizes were collected using trawl net. The results show that P. microdon possesses characteristics of carnivorous species with terminal large mouth bearing with canine teeth, short and sparse gill rakers, short esophagus with thick wall, pyloric cecum formed by 3-8 appendices, relative short intestine in S-shape. The relative short gut (relative length of gut – RLG < 1) suggests that they are carnivorous, as evidenced by food composition mainly from fishes, shrimps, mantis shrimps, krills, and crabs. Food composition is not significant differences among fish sizes suggesting this species does not change their feeding habit during life stages.

The effect of density on technical and financial efficiency of freshwater prawn (Macrobrachium rosenbergii) culture in integrated rice – prawn system in brackish area was conducted to find out the optimal stocking density. The experiment was completely randomized designed in 3 different densities treatments (NT1, NT2 and NT3) in correspondence to 1.5, 2 and 2.5 juveniles/m2 and triplicate each. The initial mean weight of juveniles was 12.7 ± 2.14 g. Salinity in the rice field varied in the range of 0‰ to 7‰. The results show that water quality parameters, density of planktons and benthos were in the suitable ranges for prawn growth. After 100 days of culture, the final mean weight of prawn in NT1 was 39.7 ± 0.38 g, which was significantly different (p

The study was conducted to evaluate the effect of the interval of 2% Premna serratifolia extract on immune response and disease resistance of striped catfish (Pangasianodon hypophthalmus). The experiment was completely randomized design with 3 treatments including 2 supplemented treatments of 2% Premna serratifolia leaf extract with different interval supplementation, 2 weeks/ month (week 1st, 2nd and 5th, 6th ) and for 4 weeks (week 1st to 4th), and a control treatment (without herbal extract) for 8 weeks, each treatment was replicated 4 times. Hematological and immunological parameters including blood cells count, lysozyme, complement activity and phagocytic activity were monitored at 2nd, 4th and 8th week of the experiment. After 8 weeks of P. serratifolia extract supplementation, fish were challenged with Edwardsiella ictaluri pathogenic strain. Results showed that the immunological parameters supplemented treatments were higher than those of control. Treatment of 2% P. serratifolia extract supplementation with 2-week interval stimulated the innate immune system of fish. The accumulative mortality of fish in treatment of 2% P. serratifolia extract supplementation with 2-week interval were also significantly lower than those in the control treatment. These results addressed that P. serratifolia extract supplementation with 2 weeks interval could enhance fish health and protect striped catfish from E. ictaluri infection.

This study was conducted to assess the effects of salinity on the distribution of Polychaetes in the shrimp culture areas of Soc Trang (ST) province. The study was implemented with 4 sampling times in March, June, September, and December, 2019 at 10 sites (from ST1 to ST10) starting from the estuaries upward the inland area. The benthic samples including polychaetes were collected in ten replicates of  each site at the cross section of the river and 5-10 m far from the riverbank. Samples were preserved with 8-10% formalin. The results showed that a total of 9 polychaetes species belonging  to 7 genus, 5 families and 3 orders was recorded. The number of taxa obtained from 10 sampling sites was 2 to 5 species. The polychaetes biomass fluctuated from 0 to 6,307 inds/m2 and there was no individual found at ST5 site (in March) and ST2 (in June). The similarity of polychaetes between the sampling site, sampling times and water salinity in the study area was obvious. Overall, salinity distinctly affected  the distribution of polychaetes in species composition (8 species recorded in salinity

The study was conducted from August to December 2018 through interviewing 106 fishermen in Tran De, Cu Lao Dung, and Long Phu districts in order to assess the current status of the fisheries in Soc Trang province. The results showed that there are 11 major kinds of fishing gears, in which trawl net (40%) and push net (35%) are the most common fishing gears in Soc Trang. The results also indicated that the mesh size (2a, mm) of trawl net 2a= 19.3 mm is smaller than the fisheries regulations. Fishing seasons are all year round; however, the main fishing season is from the first - fourth month of lunar calendar. Push net and coastal bag-net fisheries earned the highest profit while the river bag-net fishery is the lowest profit. For the fisheries management, the registered fishing gears were only 53%, trained fishermen (54%), involved in fisheries management activities (73%) and 92% of fishermen stated that fisheries resources are over-fishing (60%).

The study is aimed to determine the supplementation of sugar to achieve a ratio of C/N for the best growth and survival of white leg shrimp larvae and postlarvae. The experiment included five treatments of sugar supplement to achieve different C/N ratios as 10, 15, 20, 25, and 30; each treatment was triplicated; stocking density was 150 larvae/liter, and water salinity was 30‰; the experimental tank was 0.5 m3 in volume. Results of the experiment showed that the body length of postlarvae 12 (10.53±0.07 mm) in the sugar treatment to achieve C/N=20 was the highest and significantly different (p>0.05) compared to the sugar treatments with C/N=10, and C/N=15. The survival rate (60.9±1.4%) and productivity (91,449±2,094 ind/m3) of PL-12 in the sugar treatment with C/N=20 were also the highest and significantly different (p

Artificial intelligence (AI) is often used in the classification of images. In this study, AI algorithms have been used in combining with SURF features, K-mean clustering on a 6-class shrimp disease dataset. In order to find the most appropriate model for image classification of shrimp diseases, the study has been tested on four AI models including Multinomial Logistic  Regression, Naïve Bayes, K Nearest Neighbors, and Random Forest. Criteria for evaluating the accuracy of these models include Precision, Recall and F1. Testing results when applying with initial feature dataset show a low accuracy that the best model is Random Forest algorithm, with Recall evaluation criterion of 47.7%. The study has been continued to conduct random combinations of 4 clusters classified by K-mean algorithm, the results indicate that the Random Forest model can get highest accuracy of 85.9% by Recall criteria.

This study is performed to assess the fluctuation of rotifer compostion and its density by the effect of the variation in salinity on the lower Hau River. These results will be the principle of the research on the water quality management to supply for the sustainable development of aquaculture under the increase of saline intrusion circumstances in the Mekong Delta. The water quality and rotifers samples were collected monthly from July 2017 to June 2018 for high tide and low tide at 3 sampling sites including Cai Con, Dai Ngai, and Tran De. In the result, 47 species of rotifer were recorded in downstream region of Hau river with the density ranged of 38,985-79,761 ind.m-3 (1,249-2,045 ind.L-1 on average). The salinity had a significant effect on rotifer’s structure; in which, the amount of appeared species (Y1) and its density (Y2) were negatively correlated with salinity by 2 regression equations: Y1=-1.47*X+23.3 (where, X: salinity; R12=0.537; sig.=0.003); Y2=-529.49*X+17,045.9 (R22=0.354; sig.=0,025). The salinity of 0-4‰ was suitable for improvement of rotifer in downstream region of Hau river. At the period of low saline (less than 4‰), the farmers could have supplied the organic matters to enhance the density of rotifers such as B. plicatilis, F. terminalis. and K. cochlearis for aquaculture.

This study was conducted to investigate the antioxidant property of the extracts from three edible mushroom species, including Volvariella volvacea, Pleurotus sajor-caju, and Flammulina velutipes, which can be used in seafood storage. The aqueous extracts of these mushrooms were prepared by hot water at 95 ± 2oC in 1 hour. The antioxidant activity of aqueous mushrooms extracts was evaluated throughout the capacity of eliminating free radical DPPH and the total phenolic compounds presented in the extracts. A further assessment was performed to examine the antioxidant efficiency of mushroom extracts supplemented in salmon oil at 60oC by measuring peroxide value (PV) and thiobarbituric acid reactive substances (TBARS). The results showed that IC50 values of Volvariella volvacea, Pleruotus sajor-caju, root of Flammulina velutipes and stem of Flammulina velutipes were 618 µg/mL, 919 µg/mL, 1114 µg/mL and 1354 µg/mL, respectively. Total phenolic content the extract from Volvariella volvacea, root of Flammulina velutipes, Pleruotus sajor-caju and stem of Flammulina velutipes were 0.60 mgGAE/100mg; 0.51 mgGAE/100mg; 0.43 mgGAE/100mg and 0.23 mgGAE/100mg, respectively. Mushroom extracts could be used for storage of salmon oil at 60oC through their antioxidant capacity during 12 days of storage.